This section provides background information related to the present disclosure which is not necessarily prior art.
In some vehicle tires, especially heavy duty off-road vehicles including those used as large dump or hauling trucks, front end loaders, and those used in mining vehicles, a liquid is commonly present inside the tire to assist in cooling the tire/wheel assembly. The liquid can have some or all of the following functions: tire cooling, tire sealing, lubrication, anti-rust or descaling, tire bladder conditioning and the like. It is known to install wireless tire monitoring sensors having a sensing chip that can sense tire chamber conditions and also wirelessly transmit data such as tire pressure and temperature to remote receivers, for example receivers located in a vehicle cab or to further remote monitoring systems. Present wireless air pressure monitoring sensors have a short air passage for communication between the air inside the tire chamber and the sensing chip. It is possible for the liquid in the tire chamber to submerge the tire pressure monitoring sensor or splash on it and thus have the liquid enter the sensor through the breathing hole. Entrance of the cooling liquid can clog the air breathing hole and/or damage the internal electronic unit. If the air pressure monitoring sensor is submerged in the liquid, if additional air is pumped into the tire, the increased air pressure forces the liquid into the air pressure monitoring sensor through the breathing hole. Further, even if the air pressure monitoring sensor is not submerged in the liquid, when the tire rotates the liquid can be splashed on the air pressure monitoring sensor and enter the air pressure monitoring sensor.
U.S. Pat. No. 7,538,660 discloses a communication hole 71 and a U-shaped pipe 580 intended to prevent entrance of a tire repair agent. These features do not prevent entrance of liquid into the communication hole, particularly if the pipe 580 is submerged in a liquid. U.S. Pat. No. 8,138,904 discloses branched path sections and wall sections intended to minimize entrance of fluids by providing direct impingement of incoming fluid against the perpendicularly configured wall sections and the tortuous path of branched path sections. These features also do not prevent the entrance of liquid if the sensor is submerged.